Callipeltins and Papuamides -novel families of cyclic depsipeptides- were shown to possess potent anti-HIV activity as well as cytotoxicity against several multidrug resistant cancer cell lines. The novel structural features and diverse biological effects of these peptides metabolites have generated considerable interest among synthetic chemistry groups. In this book, discovery of the lanthanide catalyzed transamidation of Fmoc protected lactams, solid-phase synthesis and configurational reassignment of Callipeltin E, synthesis of N-Fmoc- (2S,3S,4R)-3,4-dimethylglutamine and an efficient...